The present invention relates to a cap for food, medicine, beverage containers and other perishables More particularly, the invention relates to a screw/lug or lift-up cap for attachment to bottles or other containers where said cap incorporates a lifetime indicator.
Consumer awareness of product freshness has led to the widespread practice of addressing this issue by means of appropriate product labeling. Where relevant, the label will typically provide information related to the freshness and suggested storage method of the product. This information may include a date of manufacture, a xe2x80x9csell byxe2x80x9d date, or a xe2x80x9cbest beforexe2x80x9d date. A xe2x80x9csell byxe2x80x9d date specifies by which date the product should have been sold to the consumer. A xe2x80x9cbest beforexe2x80x9d date specifies by when the product should be disposed of by vendor or consumer.
The recommended storage method typically specifies whether the product is to be stored in the refrigerator or freezer and whether this storage method is to be used from the time of purchase or from the time of first opening. The former method is typically used for dairy products, whereas the latter method is usually more appropriate for jams, sauces conserves and liquid medications. For some items the labeling will also specify for how long the product may be kept after it has first been opened. The reasoning behind this is that if the product is produced and packed under sterile conditions, first contamination can only occur following this first opening.
A number of products have been developed and commercialized that implement the concept of active labeling. These products contain a closed chemical system which changes color either as a function of elapsed time since activation, or by integrating time and temperature since activation. The latter are termed TTIs (time-temperature indicators) whereas the former merely indicate the passage of time. The specifications of a TTI can be set to emulate those of the foodstuff in the package. Thus, given that the TTI is placed on the package and activated as the food is produced, the TTI gives an accurate indication of the food freshness which takes into account the vagaries of the distribution chain. In particular, if the product has not been maintained at the appropriate temperature through a part of the distribution chain, the TTI will give the consumer an indication thereof.
U.S. Pat. Nos. 4,292,916, 5,053,339 5,446,705 and 5,633,835 describe color changing devices for monitoring the shelf-life of perishable products. These devices are initiated by physically bringing into contact reactive layers so that the reaction will start, and this action can only conveniently be performed at the time of packaging. This approach is suitable for monitoring the degradation of foodstuffs which lose freshness throughout the entire distribution chain. U.S. Pat. No. 5,555,223 describes a process for attaching timing indicators to packaging, including the step of setting the timer clock at the exact time of production.
However, there is a substantial proportion of food and drug stuffs, and other perishables for which significant degradation starts to occur only when the package is opened. For these perishables the existing timers and TTIs are likely to produce misleading results in that they have no simple and foolproof means of activation at the time of opening the package.
It is therefore the intention of the present invention to obviate the shortcomings of the above-mentioned solutions by providing a simple and appropriate means of activating a lifetime indicator for foodstuffs medicines and other perishables which have long shelf lives but deteriorate after opening. Thus, in the present invention, a key element is the use of an opening method which activates the lifetime indicator.
Numerous examples of intelligent opening mechanisms are known in the art. The simplest are tamper-evident mechanisms whereby a clear indication is provided after first operation that the packaging has been opened. Examples are found in U.S. Pat. Nos. 4,570,825, 4,572,387, 5,115,929 and 5,829,613.
Also known in the art are indicator caps, primarily intended for medicine containers, where the time of taking the dosage is shown on the cap. U.S. Pat. Nos. 3,960,713 and 4,920,912 both use a time dial in the cap that may be swiveled to show the desired time, typically that of the next dosage. U.S. Pat. Nos. 5,009,338, 5,229,701 and 5,261,548, all by Baker, A. et al describe caps with mechanical mechanisms that automatically advance the setting on the time dial to the next position, each time the cap is replaced. U.S. Pat. No. 5,358,117 describes the use of a pointer mounted in the cap to point to the time when the next dosage is to be taken. U.S. Pat. No. 5,720,392 describes a cap with an embedded clock face and with two pointers; one showing when medication was last taken and the other showing when the next dose is due.
Also known in the art are automatic timers built into bottle caps activated by the engagement of the cap relative to the bottle in order to give an alarm at the time the next dosage is to be taken. U.S. Pat. No. 4,367,955 describes a timer cap which is activated by the engagement of the cap with the container. The timing device that it incorporates is described as being either an electronic timing circuit or a mechanical escapement mechanism. In the latter case the turning of the cap on closure of the container winds up the mechanism mainspring. In both cases, both an audible and a visual signal is given at the time that the next dosage is to be taken. Similar electronic timing mechanisms are described in U.S. Pat. Nos. 5,233,571 and 5,313,439. U.S. Pat. No. 5,457,665 describes a mechanical timer in a cap, implemented by means of a sphere which slowly ascends through a tube containing a viscous solution, however said mechanism is gravity and orientation dependent.
It is therefore the object of the present invention to provide a food or medicine lifetime indication for foodstuffs medicines or other perishable which have long shelf lives but which start to deteriorate significantly after initial opening of the package. It is a further object of the present invention to ensure maximum ease of use and foolproof operation by ensuring that the action of opening the package activates the indicator.
In a preferred embodiment of the present invention, said indicator is integrated into a container or bottle cap such that the first opening of this cap activates the indicator.
In preferred embodiments of the present invention said indicator is either an elapsed time indicator or a temperature-time indicator.
Thus, according to the present invention there is now provided a cap for a hermetically sealed container, said cap providing a visually observable indication of elapsed time from the opening of the seal of said container, said cap including means for releasing a chemical which effects a color change in a chamber formed therein, said chamber being provided with a transparent section for viewing the contents thereof and said released chemical effecting a cumulative color change of said section with time, the arrangement being such that manipulation of said cap to open said container and said seal effects activation of said releasing means.
In a first preferred embodiment of the present invention there is provided a cap for a hermetically sealed container, said cap providing a visually observable indication of elapsed time from the opening of the seal of said container, said cap including means for releasing a chemical which effects a color change which traverses a chamber formed therein, said chamber being provided with a transparent section for viewing the contents thereof and said released chemical effecting a cumulative, progressive, graphic color change of said section with time, the arrangement being such that manipulation of said cap to open said container and said seal effects activation of said releasing means.
In a second type of preferred embodiments of the present invention there is provided a cap for a hermetically sealed container according to claim 1, said cap providing a visually observable indication of elapsed time from the opening of the seal of said container, said cap including means for releasing a chemical which effects a temperature dependent color change in a chamber formed therein, said chamber being provided with a transparent section for viewing the contents thereof and said released chemical effecting a color change of said section with time and temperature, the arrangement being such that manipulation of said cap to open said container and said seal effects activation of said releasing means.
In preferred embodiments of the present invention said cap comprises at least two parts movable relative to each other and having said chamber formed therebetween, at least one of said parts being provided with said transparent section for viewing said chamber.
Preferably one of said parts includes a recess having a fluid-containing capsule and said other part is provided with a protrusion which is brought into alignment with said recess on opening of said container and is adapted to rupture said fluid-containing capsule.
In especially preferred embodiments of the present invention said chamber contains a porous strip for controlled migration of said chemical and said porous strip can preferably be formed of micro-porous material.
As will be realized, the object of the present invention can be carried out in various manners, as also described in the examples hereinafter, by utilizing various color change reactions and/or dyes.
Thus, e.g., said chamber is provided with a strip containing a color-changing indicator in a porous medium and a liquid reagent which slowly diffuses along said medium to cause a color change, said reagent being released as a result of the movement of said two parts of said cap relative to each other.
Alternatively, said chamber is provided with a strip containing a reagent in a porous medium, and said capsule contains a color-changing indicator which slowly diffuses along said medium to cause a color change, said indicator being released as a result of the movement of said two parts of said cap relative to each other.
As indicated, in preferred embodiments of the present invention said chemical effects a reaction involving a color change in combination with a reagent held in said chamber, e.g., wherein said reaction is based on the interaction between a chelating agent and a metal ion solution, or said reaction is based on the interaction between a pH indicator and a base, or said reaction is based on the interaction between a pH indicator and an acid, or said reaction is based on the interaction between a redox indicator and a reducing agent, between an enzyme and a substrate system, or said reaction is based on the interaction between a redox indicator and an oxidizing agent.
In one of the preferred embodiments of the present invention said chemical is a dye and said dye slowly migrates through a porous medium, wherein said medium is at least partially visible through a transparent section in the cap, resulting in a color-change front which progresses along said medium thereby graphically showing the passage of time.
The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood.
With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.